Machine to machine communications (short M2M communications) refer to technologies wherein devices can communicate with each other. The advancement in technology has introduced a large number of different applications wherein machine to machine communications (hereinafter also called machine type communications, MTC) may be used.
Because of the wide variety of different kinds of devices standardization in the field of machine type communications has been initiated in order to provide efficient communications. A known problem arises due to large number of MTC UEs (User equipments); the number of MTC UEs may eventually be much higher than the number of the ordinary terminals. To cope with a large number of UEs in the network, the resources reserved for the MTC UEs in the network, and the signalling generated by them, need to be minimized.
Proposals for the above mentioned problem have been discussed. One proposal is to detach the UEs from the network. That is, the UEs are forced to offline state. However, these UEs still need to be triggered, even though they are not reachable by ordinary paging mechanisms. Therefore, specific trigger offline user equipments needs to be applied. The introduction of new features in 3GPP specifications impacting UEs is typically time-consuming. Therefore, the modifications should preferably such that only the network elements need to be upgraded. Alternatively, the modifications should be based on the existing 3GPP specifications. One such alternative is to use CBS (Cell Broadcast System), so that the detached UEs receive the broadcast messages, which are transparent to 3GPP specified network. These messages can contain trigger commands. A drawback of this solution is that in order to implement it in LTE devices, modifications are required to LTE (Long Term Evolution) devices specifications because CBS is not supported in the LTE. Another solution is to use MBMS (Multimedia Broadcast Multicast Services). These services may be implemented in the user equipment. However, implementing MBMS or CBS are not preferable in low cost machine type communication user equipments.
Thus, there is a need for a method where the network resources are minimized, but the implementation overhead is kept in the minimum.